package oop11;

/**
 * @author oldliu
 * @since 1.0
 */
public class USBDianya {
    public static void main(String[] args) {
        System.out.println("usb设备的工作电压是："+Usb.V);//static
        //Usb.V=3.5;//error,说明是final
    }
}
